Process for dyeing or printing fibrous materials of aromatic polyesters



United States Patent ()fiice No Drawing. Filed Jan. 24, 1961, Sen. No. 34,522 Claims priority, application Switzerland Jan. 27, 1960 9 Claims. (Cl. 8-39) This invention is based on the observation that valuable dyeings can be produced on fibrous materials of aromatic polyesters, more especially polyethylene terephthalates, by using a dyestuff a S-acylamino-isothiazoleanthrone of the formula ACOBIIH (H) in which A represents a benzene or pyridine radical, and in which the radical A or the anthrone radical may contain further suhstituents.

The S-acylamino-isothiazole-anthrones used in the process of the invention can be obtained in known manner by reacting a -amino-isothiazole-anthrone with a benzoyl halide, especially benzoyl chloride, or a pyridine carboxylic acid chloride, especially pyridine-S-carboxylic acid chloride.

For dyeing the aforesaid dyestuffs are advantageously used in a finely divided form and the dyeing is carried out in the presence of a dispersing agent, such as sulfite cellulose waste liquor or a synthetic detergent, or a combination of different wetting and dispersing agents. Generally it is of advantage before the dyeing operation to convert the dyestufi" into a dyestufi preparation which contains a dispersing agent and the finely divided dyestufi in such a form that by mixing the dyestufi preparation with Water a fine dispersion is obtained. Such dyestufi preparations can be made in known manner, for example, by grinding the dyestuit in the dry or wet state in the presence or absence of a dispersing agent during the grinding operation.

In order to produce strong dyeings on polyethylene terephthalate fibers it is of advantage to add to the dyebath a swelling agent, or to carry out the dyeing process under superatmospheric pressure at a temperature above 100 C., and advantageously at 120 C. As swelling agents there may be used aromatic carboxylic acids, for example, benzoic acid or salicyclic acid, or phenols, for example, orthoor paraoxy-diphenyl; aromatic halogencompounds for example chlorobenzene, ortho-dichlorobenzene or tri-chlorobenzene, phenyl-methyl-carbinol or diphenyl. When the dyeing is carried out under pressure it is of advantage to render the dyebath weakly acid, for example, by the addition of a weak acid, for example, acetic acid.

The dyestuffs used in the invention are especially suitable for dyeing by the so-caller thermofixation method, in which the fabric to be dyed is impregnated with an aqueous dispersion of the dyestuff, which advantageously contains 1 to 50% of urea and a thickening agent, especially sodium alginate, the impregnation being advantageously carried out at a temperature not exceeding 60 C., and the impregnated fabric being squeezed in the usual manner. Advantageously, the squeezing is carried out so that the impregnated material retains 50 to 100% of its weight of dye liquor.

in order to fix the dyestuif the impregnated fabric, ad-

3,100,132 Patented Aug. 6, 1963 vantageously after being dried, for example, in a warm current of air, is heated to a temperature above C., and especially at a temperature within the range of C. to 210 C.

The aforesaid thermofixation method is especially useful for dyeing mixed fabric of polyester fibers and cellulose fibers, especially cotton. In this case the padding liquor contains, in addition to a 5-acylamino-isothiazole anthrone, a 'dyestuif suitable -for dyeing cotton, for example, a direct dyestuff or a vat dyestuff, or more especially a so-called reactive dyestuif, that is to say, a dyestufi capable of being fixed on cellulose fibers with the formation of a chemical bond, for example, dyestuffs which contain a chlorotriazine or 'chlorodiazine radical. In the latter case it is of advantage to incorporate with the padding solution an acid-binding agent, for example an alkali metal carbonate or alkali metal phosphate, borate or penborate or a mixture of these substances. When vat dyestuffs are used it is necessary, after the heat treatment, to treat the padded fabric with an aqueous alkaline solution of a reducing agent of the kind customarily used in vat dyeing.

The dyestuils produced by the process of this invention are advantageously subjected to an after-treatment, for example, by heating them with an aqueous solution of a non-ionic detergent.

The process of this invention is also suitable for dyeing nixed fabrics of polyester fibers and wool fibers, the wool component remaining reserved and, if desired, being subsequently dyed with a wool dyestufi.

Instead of applying the dyestuffs by impregnation, they may be applied by printing. For this purpose there is used, for example, a printing color which contains, in addition to the usual auxiliary agents used in printing, such as a wetting agent or thickening agent, the finely dispersed dyestuff, if desired, in admixture with one of the aforesaid cotton dyestufiis, and, if desired, in the presence of urea and/or an acid-binding agent.

By the process of this invention there are obtained strong 'full dyeings or prints having excellent properties of wet =fastness and especially of excellent fastness to light and sublimation.

As compared with the isothiazole-anthrone described in U.S. Patent No. 2,715,128, patented August 9, 1955, to Paul Grossmann et al., which contain in the 5-position an aliphatic acylamino group, the S-acylamino-isothiazoleanthrone used in the process of this invention are distinguished by the improved fastness to sublimation of their dyeings and prints.

The following examples illustrate the invention, the parts and percentages being by weight:

Example 1 1 part of an aqueous paste of the dyestulf of the formula is ground with approximately 1 part of dry sulfite cellulose waste liquor in a roller mill to form a fine paste having a dyestufi con-tent of about 10%. a

100 parts of a fibrous material of polyethylene terepththalate are first cleaned for /2 hour in a bath containing, in 1000 parts of water, 1 to 2 parts of the sodium salt of N-benzyl- -heptadecyl-benzimidazole disulfonic acid and 1 part of a concentrated aqueous solution of ammonia. The material is then entered into a dyebath consisting of 3000 parts of water in which have been dispersed the dyestuil paste obtained as described above with the use of 4 parts of the sodium salt of N- benzyl- -heptadecyl-benzimidazole disulfonic acid. The whole is heated in an autoclave at 120 C., and maintained at that temperature for about /2 hour. The material is then thoroughly rinsed and, if necessary, washed for /2 hour at 60 to 80 C. with a solution which conrains, in 1000 parts of water, 1 part of the sodium salt of N-benzyl a heptadecyl-benzimidazole disuifonic acid. There is obtained a pure yellow dyeing of excellent fastness to light and sublimation.

By using as the dyestuff of S-nicotinylamino-isothiazoleaanthrone there is obtained a greenish yellow dyeing of excellent fastness to light and sublimation.

The S-nicotinyl-amino-isothiazole-anthrone can be prepared as follows:

37 parts of nicotinic acid are suspended in 500 parts of dry nitrobeuzene and, after the addition of 39 parts of thionyl chloride and 26 parts of pyridine, the whole is slowly heated to 115 to 120 C. while stirring. After stirring the mixture for 2 hours at 115 to 120 C., there are introduced into the solution of the acid chloride 50 parts of 5-arnino-isothiazole-anthrone and 36 parts of pyridine, the temperature is raised to 125 to 130 C. and the whole is stirred for a further 3 hours at that temperature. After cooling the mixture, it is filtered with suction to remove the precipitated dyestufl at C., washed with a small amount of nitrobenzene and hot alcohol, and dried in vacuo at 70 C.

Example 2 100 parts of a fibrous material of polyethylene terepththalate are first cleaned for /2 hour in a bath containing, in 1000 parts of water, 2 parts of the sodium salt of N-bcnzyl-a-heptadecyl-benzimidazole disulfonie acid and 1 part of a concentrated aqueous solution of ammonia. Then the material is entered into a dyebath which contains, in 3000 parts of water, 9 parts of diammonium phosphate, and 1.5 parts of the sodium salt of N-benzyl-u-heptadecyl-benzirnidazole disulfonic acid, the material being treated for minutes at 50 C. in the dyebath. 9 parts of sodium ortho-phenyl-phenolate are dissolved, slowly added, and then the liberated orthophenyl-phenol is taken up by the textile material by moving the latter in the bath for 15 minutes at 50 to 55 C. The dyestuif paste prepared as described in the first paragraph of Example 1 is then added. The bath is then brought to the boil in the course of /2 to hour, and dyeing is carried on for l to 1 hours as close as possible to the boiling temperature. The material is then rinsed well and, if desired, washed for V2 hour at 60 to 80 C. with a solution containing, in 1000 parts of water, 1 part of the sodium salt of Nbenzyl-a-heptadecyl-benzimidazole disulfonic acid. There is obtained a yellow dyeing of excellent fastuess to sublimation and light.

7 Example 3 There are mixed together 300 parts of gum arabic (1:1) 300 parts of crystal gum (1:2) 250 parts of water 40 parts of cyclohexane 40 parts of thiodiglycol 50 parts of a solution of 10% strength of the sodium salt of meta-nitrobenzenesulfonic acid and parts of a mixture of potassium oleate and pine oil 1000 parts 200 parts of the dyestutf obtained as described in the first paragraph of Example 1 are stirred in 800 parts of the above stock thickening with the aid of a high-speed stirrer until the dyestufl is completely dispersed. A fabric of polyethylene terephtha'late fibers is printed with the paste. After being printed, the fabric is dried and c5. steamed for minutes under atmosphere (gauge) pressure, then rinsed for 10 minutes in cold water, centrifuged and dried. There is obtained a fast yellow print.

Example 4 200 parts of urea and 20 parts of the dyestulf of the formula are dissolved in 400 parts of water at the boil. There is then poured into the solution 100 parts of an aqueous dispersion containing 30 parts of S-benzoylamino-isothiazole-anthrone and 2 parts of the sodium salt of diisobutyl naphthalene sulfonic acid, the whole is thoroughly mixed for a few minutes with a high-speed stirrer and there are simultaneously added 100 parts of a solution of 20% strength of sodium carbonate and 400 parts of a solution of strength of sodium alginate.

A mixed fabric of 35 parts of cotton and 65 parts of polyethylene terephthalate fibers are padded with the resulting padding solution at 50 to C. in such manner that the impregnated fabric retains to of its weight of dyestuff solution, the fabric is then dried and subjected to -a heat treatment for one minute at 200 to 210 C.

The fabric is then washed for 20 minutes in a solution containing, per liter, 2 grams of a non-ionic detergent and 2 grams of calcined sodium carbonate, at the boil, and the fabric is then rinsed and dried. There is obtained a pure yellow dyeing having very good properties of fastness.

Example 5 50 parts of urea are dissolved in 300 parts of water. Into the solution are poured 100 parts of an aqueous dispersion containing 100 parts of S-benzoylamino-isothiazole-anthrone and 3 parts of the sodium salt of diisobutyl-naphthalene sulf-onic acid and also parts of a finely dispersed paste of the dyestuff of the formula the whole is thoroughly mixed for a few minutes with a high-speed stirrer, during which pants of a solution of 20% strength of sodium carbonate and 300 parts of a solution of 25% strength of sodium alginate are added.

A mixed fabric of 35 parts of cotton and 65 parts of polyethylene terephthalate fibers is padded with the padding solution so obtained at 55 C. so that the impreg; nated fabric retains 100% of its Weight of dyestuff solution, the fabric is then dried and subjected to a heat treatment for one minute at 200 to 210 C.

100 parts of the material so treated is then passed in a ji-gger 6 times through 500 parts of a solution, heated to 60 C., containing in 1000 parts of water 35 parts of caustic soda solution of 300% strength and 12 parts of sodium hydrosulfite. The fabric is then rinsed with cold Water and for 20 minutes at 40 C. with a solution containing in 1000 parts of water 5 parts of a hydrogen peroxide solution of 30% strength and 5 parts of an acetic acid solution of 40% strength.

The fabric is then rinsed again and washed for 30 minutes in a solution containing in 1000 parts of water 2 parts of a non-ionic synthetic detergent and 2 parts of calcined sodium carbonate at the boil, then rinsed and dried. There is obtained a pure yellow dyeing having very good properties of tastness.

The cotton component may be dyed in the usual manner after the dyeing of the polyester component.

Example 6 100 parts of a mixed fabric of 50 parts of polyethylene terephthalate fibers and 50 parts of wool are entered at 50 C. into a dyebath containing in 1000 parts or water 5 parts of an aqueous emulsion of 75% strength of the salicylic acid methyl ester as accelerator, 1 part of the sodium salt of di-isobutylnaphthalene sulfonic acid and par-ts of 5-'benz0ylamino-1:9-isothiazole-anthrone. The whole is then brought to the boil in the course of one hour, and boiled for 1 /2 to 2 hours. The dyed material is well rinsed with warm water. Subsequent cleaning is not necessary.

The polyester component is dyed a strong yellow tint, and the wool component remains reserved and almost white.

What is claimed is:

1. A process of dyeing and printing polyethylene terephth-alaite which comprises applying to fibrous materials 'of polyethylene terephthalate an aqueous dispersion containing a 5-acylamino-isothiazole-anthrone of the formula II I A-C OII\IH ii in which A represents a member selected from the group consisting of benzene and pyridine radicals as the essential color imparting substance.

2. A process as claimed in claim 1, wherein 5-benzoy1- amino-isothiazcle-anthrone is used.

3. A process as claimed in claim 1, wherein S-nicotinylaminoisothiazole-anthronc is used.

4. A process as claimed in claim 1, wherein the material to be dyed is padded with an aqueous dispersion or the dyestufi and the impregnated material is subjected to the action of dry heat.

5. A process as claimed in claim 4, wherein the impregnated material is heated at a temperature Within the range of R to 210 C.

6. A process as claimed in claim 4, wherein the padding liquor contains urea.

7. Polyethylene terephthlalate fibers dyed with a 5- acylarnino isolthiazolewanthrone of the formula A-C O-NH in which A represents a member selected fnorn the group consisting of benzene and pyridine radicals.

8. Polyethylene terephthalate fibers dyed with S-gbenzoylamino-isothiazole-anthrone.

9. Polyethylene terephthalate fibers dyed with S-nicotinyl amino-isothiazole-anthrone.

References Cited in the file of this patent UNITED STATES PATENTS 2,494,811 Holbro et a1 Ian. 17, 1950 2,715,128 Grossmann et all. Aug. 9, 1955 2,876,061 Mautner Mar. 3, 1959 2,979,498 Andrew et al. Apr. 11, 1961 3,005,833 Gutzswiller et al. Oct. 24, 1961 

1. A PROCESS OF DYEING AND PRINTING POLYETHYLENE TEREPTHALATE WHICH COMPRISES APPLYING TO FIBROUS MATERIALS OF POLYETHYLENE TEREPHTHALATE AND AQUEOUS DISPERSION CONTANING A 5-ACYYAMINO-ISOTHIAZOLE-ANTHRONE OF THE FORMULA 